Silent but Deadly?
By Matt Feagins
EVs such as the Tesla Model S and Nissan Leaf, or even plug-in hybrids like the Chevrolet Volt, are becoming more and more popular despite the fact that gas has become cheap again and is forecast to remain low for the foreseeable future. EVs are anticipated to be even more popular as they approach $30,000 (after tax credits) with a range of 200 miles or more in cars such as the Tesla Model 3 and the Chevy Volt.
Why are people buying them when they can still get gas cars that are much cheaper and have more range? The main reason these cars are popular is to be green. Some like the instant torque they offer. Others love the quiet ride a virtually silent electric engine gives to the vehicle.
But that silence has a shortcoming – pedestrians are often surprised when a silent car is suddenly upon them. Matter of fact, a 2011 NHTSA study found that these types of vehicles were involved in more pedestrian and bicycle crashes than regular old ICE (internal combustion engine) vehicles. The problem is worse during low-speed driving, under 35 mph, which is the speed at which parking garage maneuvers take place. Matter of fact, an EV/hybrid vehicle had 85 percent greater crash odds than an ICE vehicle when looking at low speed maneuvers and pedestrian-only crashes. One has to note that this study only involved hybrid vehicles and not electric vehicles, which are typically even quieter.
Clearly, this is a problem and NHTSA has proposed that hybrid and electric vehicles have minimum sound requirements to mitigate this issue. These requirements will apply to vehicles traveling less than 18 miles per hour. Unfortunately for pedestrians, full compliance won’t be required until 2018.
Matt Feagins is director of design/structures with WALTER P MOORE.